Disclosed is a liquid crystal display device which is capable of adjusting a contrast ratio by transforming and outputting input data of a reference voltage circuit. Analog voltage signal generator stores an input synchronous signal and a plurality of input digital data signal in response to a write enable signal, and converts the stored digital data signal into a plurality of analog voltage signal pairs in response to an output enable signal. A plurality of reference voltage generators divide a boosted source voltage according to the analog voltage signal pairs from the analog voltage signal generator to generate a plurality of reference voltages. A source driver integrated circuit receives the plurality of reference voltages from the plurality of reference voltage generators.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A liquid crystal display device comprising: an analog voltage signal generator storing an input synchronous signal and storing a plurality of data values, which represent a plurality of input digital data signals in response to a write enable signal, said analog voltage signal generator also converting stored digital data signals into a plurality of different analog voltage signal pairs in response to an output enable signal; a plurality of reference voltage generators for dividing a boosted source voltage according to the analog voltage signal pairs from the analog voltage signal generator to generate a plurality of reference voltages; and a source driver circuit for receiving the plurality of reference voltages from the plurality of reference voltage generators, wherein a digital/analog converter of the analog voltage signal generator changes a reference voltage value and outputs a changed value reference voltage to the reference voltage generators, to thereby change a contrast ratio according to changed reference voltage values when a command to change a reference voltage value is transferred to the digital/analog converter.
2. A liquid crystal display device as claimed in claim 1 , wherein the analog voltage signal generator includes: a data storage section, which stores the input synchronous signal and which stores the plurality of input digital data signals in response to the write enable signal; the digital/analog converter converting the plurality of input digital data signals stored in the data storage section into a plurality of analog signals in response to the input synchronous signal when the output enable signal is generated; and a buffer amplifier amplifying the plurality of input analog signals and outputting the plurality of analog voltage signal pairs.
3. A liquid crystal display device as claimed in claim 2 , wherein the data storage section stores a fixed reference voltage signal pair according to voltage-transmission factor curve feature, and the digital/analog converter changes the fixed reference voltage signal pair stored in the storage section in response to an external reference voltage change command and outputs a changed reference voltage.
4. A liquid crystal display device as claimed in claim 1 , wherein the plurality of reference voltage generators include a plurality of resistors connected to each other in series between a power supply terminal and a ground terminal for generating the plurality of reference voltages.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
September 24, 2003
August 7, 2007
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